The USA started off using metric at one time. But over time, the silly old imperial units gained more prominence, becoming known as "English" units, despite being different in their definitions to those used in England, even though most of the world was changing to metric.
Why stay in the dark ages with US Customary Units? If Obama wants change, the way forward is metrication now.
Vote now at the Obama Ideas site: http://ideas.obamacto.org/
Currently the idea to complete metrication is at number 4, with 5,535 votes, so there is a significant number of Americans who do appear to want the USA to change to metric completely. Let's hope that Obama makes it happen.
Americans can look at http://www.metrication.us/ if they need any help with using metric.
